Inverse Treatment Planning and Stereotactic Intensity-Modulated Radiation Therapy (IMRT) of the Tumor and Lymph Node Levels for Nasopharyngeal Carcinomas

Abstract

IMRT allows the treatment of the target volumes with high doses combined with an excellent sparing of the organs at risk. The IMRT approach presented here makes the treatment of the whole target volume with a single-beam arrangement feasible and does not increase the treatment time compared to a split-beam IMRT technique. Treatment time was comparable to a conventional three-field technique combined with electrons. This IMRT technique can prevent over- or underdosage at field matchlines in the head and neck region and, moreover, is able to spare parotid glands and therefore better avoid xerostomia compared to conventional techniques.

Verification of IMRT: Techniques and Problems

“…In spite of the discussed problems, IMRT is a method to spare the organs at risk and to get a sufficient dose in the PTV in one session [24,30]. The classic irradiation technique for H&N tumors, on the other hand, claims multiple fields with over-or underdosage at field matchlines of electron and photon fields and does not allow sparing the parotids.…”

Simultaneous Integrated Boost (SIB) for Nasopharynx Cancer with Helical Tomotherapy

“…Intensity-modulated radiotherapy (IMRT) for NPC and other head-and-neck cancers has been demonstrated to be an effective method for improving the therapeutic ratio [4,5,13,15,19,25,31,32,37,38,40,42]; IMRT gives also the possibility to simultaneously deliver different doses to different volumes in a very efficient way: this approach, named simultaneous integrated boost (SIB), has also some potential for improving the local control through a moderate acceleration of the treatment [15,16,24,39].…”

Local High-Dose Radiotherapy and Sparing of Normal Tissue Using Intensity-Modulated Radiotherapy (IMRT) for Mucosal Melanoma of the Nasal Cavity and Paranasal Sinuses

“…The KonRad software developed at the German Cancer Research Center (dkfz) was used for IMRT treatment planning [35,63]. The simultaneous treatment of different target volumes, here defined as GTV and CTV, with different daily fraction sizes was performed.…”